Loose joints in aforesaid switchgears produce local heat as a consequence of higher transition resistances of such loose joints. Such faults have to be detected, because in dependency of the resulting higher electrical resistance, the produced heat can rise to destructive level, but in any case it produces energy loss in the electrical network. Current practice of loose joint detection involves complex temperatures and currents measurement collected in one point for the whole switchboard, consisting of certain numbers of switchgear panels. In know switchgears, a complex map of the temperatures and currents within the switchboard is created and hot spots are detected by correlating the currents and temperatures. This is expensive because of many measuring points and centralized processing.
A further disadvantage is, that with a centralized system, it is impossible to detect a loose joint in one panel without the measurement from other switchgear panels, and it results in a complex data collection and processing.